Study of radon/thoron exhalation rate, soil-gas radon concentration, and assessment of indoor radon/thoron concentration in Siwalik Himalayas of Jammu & Kashmir

摘要

In the present study, the soil-gas radon concentration was assessed at different depth intervals, i.e., 15cm, 30cm, 60cm, and 100cm from the 30 villages of Jammu & Kashmir, India using RAD7, an electrostatic solid state alpha detector. The radon mass exhalation and thoron surface exhalation rate has also been measured in the selected 18 soil samples out of 30 of different grain sizes (i.e., 1mm, 300 mu m, 150 mu m). The active radon and thoron concentrations were also assessed in the 20 villages. Both the exhalation rates and active radon/thoron concentration were measured using SMART Rn Duo, a portable radon monitor. The average values of soil-gas radon concentration were 210 +/- 84Bq m(-3), 1261 +/- 963Bq m(-3), 4210 +/- 1994Bq m(-3), and 671 +/- 305Bq m(-3) at the depth intervals of 15cm, 30cm, 60cm, and 100cm, respectively. The exhalation rate of radon and thoron from soil was found to decrease with the increase of grain size, as smaller soil particles make relatively more contribution to radon and thoron exhalations from the ground surface than larger soil particles. The measured Pearson's correlation coefficient was obtained as statistically significant between different quantities under two-tailed test.